What kind of fraud prevention/authorization methods do you use for new accounts?
Manually verify (geoIP, match addresses, etc)?
Phone call to client?
Has anyone been able to reduce fraudulent accounts to zero or near zero with any approaches?
To answer your question directly, yes I have. From using a real time gateway and having to deal with fraud and charge backs to changing to a manual payment gateway (http://e-path.com.au) to no fraud and no charge backs.
The system is manual so you need to charge the cards into your merchant account at your bank yourself but this allows you to check the buyer's address, maybe check his/her phone number (ring up to confirm order), send an email etc. There are quite a few things I do to check first and because I'm vigilant at it so far have not had one fake order get past me. Once all is good I can ring up to get an authorisation number if I want.
Because its manual I can't see it being a good solution for those who do heaps of transactions. It took me a while to get comfortable with having to do things manually but the money its saved me is enormous. Don't know whether it would suit you but its certainly working for me as long as I follow my chekcing process.